Mercury-vapor vacuum pump



June 24, 1930. E. KOBEL 1,766,651

MERCURY VAPOR VACUUM FUMP Filed Aug. 21, 15328 5 20 fl i i i I 19 V I @3 Patented June 24, 1930 UNITED STATES PATENT OFFICE ERNST KOBEL, OF BADEN, SWITZERLAND, ASSIGNOR T0 .AKTIENGESELLSCHAF'I BROWN BOVEBI &; CIR, OF BADEN, SWITZERLAND, A JOINT-STOCK COMPANY OF SWITZER- LAND MERCURY-VAPOR VACUUM PUMP Application filed August 21, 1926, Serial No.

This invention relates to the construction of high vacuum pumps of the type which operate on the difi'usion or ejection princi ples. It pertains particularly to pumps of metal construction suitable for practical industrial service, such as the evacuating of metallic vapor power rectifiers. I

A general object of the invention is the provision of a construction which will increase the operating eiiiciency of the pump by elimination of elements which offer resistance to the flow of the handled gases.

Another object is the provision of a construction for such pumps which will facilitate assembly, and dismantling for the purpose of inspection or repair.

Other and further objects will be pointed out or indicated hereinafter, or apparent to one skilled in the art upon an understanding of the invention.

In the accompanying drawing forming a art of the specification I illustrate one emodiment of the invention, but the claims are not to be regarded as limited to this embodiment alone.

In the drawing,

Fig. 1' is a part elevational and part sectional elevational view of the inner portion of a high vacuum pump, and

Fig. 2 is a section on approximately the line 2-2 of Fig. 1.

Referring immediately to the illustrative embodiment, let it be understood that the reference numeral 10 designates a heating element or hot plate upon which is fitted the boiler or vapor generator portion 11 of the pump, which boiler contains mercury which is to be vaporized by the heat to supply the operating pressure fluid. From boiler 11 extends the casing base portion 12, which assumes the form of a cylindrical collar 14 having the outwardly bevelled upward margin or shoulder 14:. To the collar is secured, in air tight fashion, the tubular pump casing 15, the same being provided with the discharge tube 16, leading to a preliminary evacuating pump. The casing is closed at the top with a suitable air tight closure 17 to which is connected the inlet tube 18 leading from the receiver or the vessel to be 130,627, and in Germany September 9, 1925.

evacuated. Axially within the casing is supported the nozzle tube 19 having the flow reversing and expanding nozzle cap 20 supported at its upper end. The nozzle tube 19 is caried on a mounting disk 21 having a bevelled portion or shoulder 21 adapted to seat on the bevelled margin or shoulder 14 of collar 1 1, and cylindrical portions adapted to fit against the inner surfaces of the casing and the member 14. The mounting disk is anchored in place by means of pins or studs 22 seated in and projecting inwardly in radial direction from the collar member 14, said studs engaging in suitably formed bayonet slots 24 in the outer face of the disk member.

The device operates after the usual fashion of the diffusion high vacuum pump, the mercury being vaporized in the boiler 11, passing up the nozzle tube 19, and ejecting at high velocity in a downward direction from the nozzle cap 20, producing an entrainment and diffusion in it of the air drawn in through the inlet pipe 18, and through condensation of the vapor against the cooled wall of the casing, producing a relative compression at the withdrawal tube 16, through which the air is withdrawn by the preliminary pump. The disk or nozzle-supporting member 21 may be provided with axial grooves 25 to provide passages for return of the condensed mercury vapor to the boiler 11.

The construction above described affords a pump which is free of obstruction to the entering air above the nozzle. Moreover, the construction is very simple and is not subject to disarrangement in contemplated industrial use, requires no fine adjustments and permits the complete removal of all interior parts with facility simply upon-removal of the casing closure. As a result, the pump has increased capabilities in the direction of efficiency and certainty of performance.

What I claim is:

I 1. In a vacuum pump, in combination, a vapor generator, a pump casing connected thereto, said casing having an air inlet and air outlet, a nozzle mounted in the casing with its discharge end between the air inlet and the air. outlet, said casing being free of internal obstructions between the air inlet and the discharge end of a nozzle. a 2. In a vacuum pump, in combination, a

ump casing, a beveled mounting disc having bayonet slot connection with casing interiorly thereof, and a nozzle carried by the disc, and means for maintaining said nozzle in ali ent in said casing comprising a bevele member cooperating with said beveled mounting disc.

3. In a vacuum pump, a casing, a nozzle disposed therein, a mounting member having a beveled portion arranged for rotary movement within said casing and providin a support for said nozzle means within sai casing providing for a holdin connection between said casing and sai supporting means upon such movement of the latter in a given direction, said means operating to re ease said supporting means upon such movement thereof in the opposite direction, and means for maintaining said nozzle in ali ent in said casing com rising a bevele iember cooperating wit the beveled portion of said mounting member.

4. In a vacuum pump, a casing, a nozzle element disposed in said casing for rotary a0 movement about its longitudinal axis and provided with an enlarged supporting portion extending transversely across and fittingbsaid casing, means gioviding for an assem la e connection wit 'n said casing with as said en arged portion upon such movement of said nozzle element in a given direction said means operatin upon movement of sai nozzle element in t e opposite direction to release the latter with respect to said casing, 40 and means for maintaining said nozzle element in alignment in said casing comprising a shoulder on said nozzle supporting portion and a shoulder provided interiorly of said casing cooperating with said first-named shoulder.

In testimony whereof I have hereunto subscribed my name this 4th day of August, A. D. 1926, at Zurich, Switzerland.

ERNST KOBEL. 

